The present invention relates to a compressor, a spray apparatus using the compressor, and an air brush for the spray apparatus.
In particular, the present invention relates to a small, lightweight portable compressor. In the compressor, rotational drive, from a small battery powered DC motor is converted into reciprocating movement to actuate a compressing mechanism. The transmission of the reciprocating movement to the compressing mechanism causes the mechanism to continuously discharge compressed air out of a discharge hole. The invention also relates to a spray apparatus which employs the above portable compressor. The spray apparatus emits a homogeneous and fine particle spray liquid, which is effective for forming a coating over a relatively small area or a coating with a line pattern. The invention also relates to an air brush suitable for use in the spray apparatus.
Previous compressors have used rotational drive of a motor energized by an AC power source or high gas-pressure of a cylinder filled with a flon gas, an LP gas, or the like. These compressors have been used mainly as a supply source of compressed air for a spray gun, an air brush, or the like.
Compressors using an AC power source have primarily been used as large-sized stationary compressors. To obtain compressed air having a suitable discharge pressure, such compressors have required a subsidiary device such as a pressure adjusting regulator, a drain separator for exhaust drain generated owing to a high pressure, an expensive air filter for highly accurately maintaining the reciprocating movement of a piston or the like, and so on. Further, using an AC power source, the compressor has a limit in view of its use environment (e.g. place, conditions, etc.), and therefore has not been, useful as a portable light compressor.
In a high-pressure gas cylinder system, although portability is achieved, the quantity of effective use of gas per gas cylinder is small, and gas temperature is reduced due to the heat of vaporization in continuous spraying which thereby deteriorates the vaporization of the gas. This deteriorated vaporization reduces the discharge pressure making the system apt to be disabled.
Further, in a gas cylinder system, a suitable one of various kinds of gas cylinders differing in structure of their connection portions and a suitable kind of gas must be selected depending on the apparatus to be connected to the system. Therefore, an exclusive cylinder must be prepared, but there has been a problem in atmospheric pollution due to the flon gas and danger due to the combustible gas.
Japanese Utility Model Unexamined Publication Nos. 56-85079, 60-122583, for example, have proposed portable air pumps in which a motor and a driving portion are housed within a casing and battery actuated.
The respective air pumps disclosed in Publication Nos. 56-85079 and 60-122583 have mechanisms for discharging air through expanding/shrinking of a bellows and through vibrations of a diaphragm, respectively. However, these air pumps cannot satisfy the necessary requirements for use with a spray gun and an air brush because each pump not only has a low discharge pressure and a low flow rate but also pulsating air.
Further, e.g. Japanese Utility Model Post-Exam Publication No. 58-11387 discloses a spray apparatus in which a motor and a driving element are housed within a casing, and in which a liquid to be sprayed is pressurized and atomized directly by means of a pump. This spray apparatus is, however, not suitable for forming a coating in which a homogeneous coated-film is required although the apparatus is suitable for spraying a medical liquid or the like, because the particle size of the atomized liquid is relatively large.